1. Field of the Invention
This invention relates to the harvesting of flue-cured tobacco by mechanical means.
2. History of the Related Art
Bright leaf flue-cured tobacco was developed during the 19th century. Harvesting by hand involved removing two to four leaves at numerous pickings over a period of several weeks and stringing the leaves on a stick for curing, all of which involved a great deal of manual labor. In more recent times vehicles for leaf picking workmen have been produced with conveyors for the leaves, and bulk harvesting and curing bins, have generally supplanted leaf stringing and stick curing in barns. Machines to mechanically strip the leaves have been made but accompanied by problems.
The U.S. Pat. Nos. 3,695,014 and 4,038,808, assigned to Clemson University, disclose a harvester having mechanical leaf strippers. Other mechanical leaf strippers are shown in the U.S. Pat. Nos. 3,093,949, to Splinter 3,466,856, to Rakestraw 3,999,359, to Jordan et al. 4,023,331, to Gregory et al. 4,391,084, to Wilson and 4,530,203 to De Cloet.
In the harvester of the two Clemson patents, the defoliator belt, itself, provides the openings for receiving the tobacco stalks. Thus, the belt elements which form the openings are in the plane of the belt and their angular disposition varies with its angularity. The horizontal dimension of the opening must be sufficient to slip over the end of the stalk with relative ease, but such opening may be too large for efficient stripping. Thus, in the later Clemson U.S. Pat. No. 4,038,808, the angularity is increased from the upper to the lower portion of the run, to reduce the effective horizontal dimension of the opening in order to improve the leaf stripping action. This also reduces the stalk height available for stripping at the reduced angle, thus rendering its stripping action less effective on the upper portion of the stalks. In addition, since the opening is effectively reduced to improve stripping, when the change of direction from downward to upward occurs the likelihood of breaking the stalk increases. An additional problem with the Clemson harvester is that the conveyor belt for removing the leaves is positioned directly beneath the defoliating belt on the upward slope and its proximity interferes with the removal of the leaves.